The geosynthetic encased column (GEC) is a relatively recent method developed for soft soil improvement. The method was firstly introduced as a concept in the 1980s and first practical applications started in the 1990s. GECs have been widely used in some parts of the world for the last three decades. However, there is no book in the literature summarizing the knowledge accumulated during this period in relation to this soft ground improvement technique.
The purpose of this book is to provide readers with the GEC fundamentals and practical applications. Chapter 1 presents the general principles of this ground improvement technique including the methods used for GEC installation and how the material properties may be selected. Chapter 2 presents the design methods, thus settlement calculations by means of analytical methods and stability calculations by limit equilibrium methods are explained in detail. Chapter 3 presents calculation examples illustrating the usual steps to be done for both service limit state and ultimate limit state designs. Then field performances exemplifying practical applications of the GEC technique are presented in Chapter 4 for some case histories. Following numerical analyses, often used in design to complement analytical methods, are presented in Chapter 5. Annexes I and II at the end contain the charts developed to perform settlement calculations.
The book combines the experiences of four authors with different academic and industry backgrounds to describe GEC design and performance. It is aimed at civil engineers in general, particularly geotechnical engineers, either working in design or in practice, at graduate students, and at senior undergraduate students.
Geosynthetic encased columns (GECs) are a relatively recent technique that is used to reduce settlements and to improve the load-bearing capacity of soft and highly compressible deposits where traditional (non-encased) stone columns are not a suitable alternative. […] There is now a large literature comprising case studies of GECs supporting embankments, and guidance on the analysis and design of these structurers. Nevertheless, there is until now no single book summarising the current knowledge for this soft ground improvement technique and recommendations for their design. The book reviewed here meets the need of design engineers for a comprehensive single source for the specification, design and analysis of geosynthetic encased columns for soft soil improvement. […] This book contains a good review of the principles behind GEC soil improvement, comprehensive calculation examples, guidelines for numerical analyses, detailed real-world project examples, and practical tips. The book is aimed at practising civil and geotechnical engineers but is also a useful resource for researchers, graduate students and undergraduate students taking advanced geotechnical foundation engineering courses.
R. J. Bathurst, Geosynthetics International, Volume 26 Issue 2, April, 2019, pp. 222-222
1.2 General principles
1.3 Applications (Alexiew and Thomson, 2014)
1.4 Execution methods
1.5 Material properties selection
2 Design methods
2.2 Vertical design: "general principles"
2.3 Vertical design: "analytical calculation"
2.4 Vertical design: consolidation analysis
2.5 Vertical design: column layout
2.6 Alternative calculation methods
2.7 Global stability: plane strain analysis
2.8 Final comments
3 Parameters used in pre-design charts and calculation examples
3.2 Limit state design
3.3 Material parameters
3.4 Vertical design: charts utilization
3.5 Calculation examples
4 Instrumented embankments on GEC
4.2 Test embankment at TKCSA, Itaguaí, Brazil, 2012
4.3 Other case studies
4.4 Final remarks
5 Application of numerical analyses
5.2 2D axisymmetric analysis
5.3 2D plane strain analysis
5.4 3D strip analysis
5.5 Final remarks